Punctal Plugs in the Management of Dry Eyes

Etiopathology, Epidemiology, Diagnosis, and Treatment of Fungal Keratitis

Fungal keratitis (FK) is a severe ocular condition resulting from corneal infection that is prevalent in tropical countries, particularly in developing regions of Asia and Africa. Factors like corneal lens misuse, inappropriate steroid use, and diagnostic challenges have provoked the epidemic. FK causes significant vision impairment, scarring, and ocular deformities. Accurate pathological diagnosis is crucial for effective therapeutic intervention. Topical antifungal therapy with surface healing medications proves effective in preventing fungal-borne ulcers. Managing FK requires a comprehensive understanding of fungal pathogenesis, guiding formulation strategies and preventive measures to curb global ocular blindness. This review provides in-depth insights into FK, covering etiology, epidemiology, pathogenesis, therapeutic interventions, antifungal resistance, limitations, prevention, and future perspectives on ocular surface disease management.

Preparation and performance of latanoprost-loaded hydrogels as a lacrimal suppository for the treatment of glaucoma

Glaucoma is the leading cause of irreversible blindness, and its treatment is attracting widespread attention. Drug-loaded lacrimal suppositories can effectively treat xerophthalmia, but there is little research on the treatment of glaucoma with drug-loaded lacrimal suppositories. This article explored and expanded the non-pharmacological model of lacrimal suppository therapy for glaucoma by using a combination of lacrimal suppository and medication. The drug-loaded lacrimal suppository was rationally designed through the conjugation of gelatin with polyamide (PAM) via the formation of amide linkages, followed by Schiff base reaction grafting with latanoprost. In vitro drug release studies showed that latanoprost released from drug-loaded lacrimal embolus had sustained-release properties with a release time of 33 days and a drug release volume of 82.6%. The biological evaluation of drug-loaded lacrimal thrombus was carried out by IOP test, retinal potential test, and retinal H&E staining. The results showed that the IOP decreased to 27.125 ± 1.1254 mmHg, and the a and b waves of retinal potential increased to 4.39 ± 0.16 μV and 67.9 ± 2.17 μV, respectively. It indicated that latanoprost lacrimal suppository has a good therapeutic effect on glaucoma.

Botulinum Neurotoxin Type a Injection Combined with Absorbable Punctal Plug Insertion: An Effective Therapy for Blepharospasm Patients with Dry Eye

Blepharospasm patients often have dry eye manifestations. Botulinum neurotoxin type A (BoNT-A) injection has been the main management for blepharospasm and absorbable punctal plug (APP) insertion is shown to be effective in the treatment of dry eye. However, there have been no studies investigating the combined treatment of BoNT-A and APP in blepharospasm patients with dry eye. In this retrospective study, 17 blepharospasm patients with dry eye treated by BoNT-A injection and 12 receiving BoNT-A plus APP treatment were enrolled. The efficacy was evaluated according to the Jankovic rating scale, Ocular Surface Disease Index (OSDI), fluorescein staining (FL), fluorescein tear break-up time (FBUT) and Schirmer I test (SIT). Both BoNT-A and BoNT-A+APP treatment effectively reduced the functional impairment of blepharospasm. At baseline, all the patients had high OSDI scores (BoNT-A group: 82.48 ± 7.37, BoNT-A+APP group: 78.82 ± 4.60, p = 0.112), but relatively low degrees of FL (BoNT-A group: 3.18 ± 1.01, BoNT-A+APP group: 3.50 ± 1.24, p = 0.466), FBUT (BoNT-A group: 1.71 ± 0.77, BoNT-A+APP group: 2.17 ± 0.58, p = 0.077) and SIT (BoNT-A group: 2.53 ± 0.99, BoNT-A+APP group: 3.17 ± 1.23, p = 0.153). After treatment, OSDI, FL, FBUT and SIT were all obviously restored in the two groups. When comparing the changing rates, only OSDI (BoNT-A group: -52.23% ± 15.57%, BoNT-A+APP group: -61.84% ± 9.10%, p = 0.047) and FL (BoNT-A group: -22.55% ± 25.98%, BoNT-A+APP group: -41.94% ± 14.46%, p = 0.016) showed significant differences between the two groups. This study suggests that OSDI is not applicable in the diagnosis of dry eye among blepharospasm patients. For blepharospasm patients with severe dry eye symptoms, especially those with fluorescein staining in the cornea, the combined treatment of BoNT-A and APP is more effective than using BoNT-A alone.

In Situ Forming Hydrogel as a Tracer and Degradable Lacrimal Plug for Dry Eye Treatment

Lacrimal plug is an effective and widely therapeutic strategy to treat dry eye. However, almost all commercialized plugs are fixed in a certain design and associated with many complications, such as spontaneous plug extrusion, epiphora, and granuloma and cannot be traced in the long-term. Herein, a simple in situ forming hydrogel is developed as a tracer and degradable lacrimal plug to achieve the best match with the irregular lacrimal passages. In this strategy, methacrylate-modified silk fibroin (SFMA) is served as a network, and a self-assembled indocyanine green fluorescence tracer nanoparticle (FTN) is embedded as an indicator to develop the hydrogel plug using visible photo-crosslinking. This SFMA/FTN hydrogel plug has excellent biocompatibility and biodegradability, which can be noninvasively monitored by near-infrared light. In vivo tests based on dry eye rabbits show that the SFMA/FTN hydrogel plug can completely block the lacrimal passages and greatly improve the various clinical indicators of dry eye. These results demonstrate that the SFMA/FTN hydrogel is suitable as an injectable and degradable lacrimal plug with a long-term tracking function. The work offers a new approach to the development of absorbable plugs for the treatment of dry eye.

The Antimicrobial Peptide Human β-Defensin-3 Accelerates Wound Healing by Promoting Angiogenesis, Cell Migration, and Proliferation Through the FGFR/JAK2/STAT3 Signaling Pathway

In addition to its antimicrobial activity, the skin-derived antimicrobial peptide human β-defensin-3 (hBD-3) promotes keratinocyte proliferation and migration to initiate the wound healing process; however, its effects on fibroblasts, which are the major cell type responsible for wound healing, remain unclear. We investigated the role of hBD-3 in cell migration, proliferation and production of angiogenic growth factors in human fibroblasts and evaluated the in vivo effect of hBD-3 on promoting wound healing and angiogenesis. Following hBD-3 treatment, the mouse wounds healed faster and showed accumulation of neutrophils and macrophages in the early phase of wound healing and reduction of these phagocytes 4 days later. hBD-3-treated wounds also displayed an increased number of fibroblasts and newly formed vessels compared to those of the control mice. Furthermore, the expression of various angiogenic growth factors was increased in the hBD-3-treated wounds. Additionally, in vitro studies demonstrated that hBD-3 enhanced the secretion of angiogenic growth factors such as fibroblast growth factor, platelet-derived growth factor and vascular endothelial growth factor and induced the migration and proliferation of human fibroblasts. The hBD-3-mediated activation of fibroblasts involves the fibroblast growth factor receptor 1 (FGFR1)/Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathways, as evidenced by the inhibitory effects of pathway-specific inhibitors. We indeed confirmed that hBD-3 enhanced the phosphorylation of FGFR1, JAK2 and STAT3. Collectively, the current study provides novel evidence that hBD-3 might be a potential candidate for the treatment of wounds through its ability to promote wound healing, angiogenesis and fibroblast activation.

In vivo drug delivery via contact lenses: The current state of the field from origins to present

Over the past half century, contact lenses have been investigated for their potential as drug delivery devices for ocular therapeutics. Hundreds of studies have been published in the pursuit of the most effective and efficient release strategies and methods for contact lens drug delivery. This paper provides a thorough overview of the various contact lens drug delivery strategies, with a specific, comprehensive focus on in vivo studies that have been published since the field began in 1965. Significant accomplishments, current trends, as well as future strategies and directions are highlighted. In vivo study analysis provides a straightforward perspective and assessment of method success and commercialization potential in comparison to benchtop, in vitro studies. Analysis of the majority of published work indicates in vitro and in vivo studies do not correlate with a correlation coefficient of 0.25, with many in vitro studies grossly overestimating drug release duration and not showing appreciable drug release control. However, there has been an increase in activity in the last decade, and some methods have generated promising results exhibiting controlled release with commercialization potential. Clinical translation of drug releasing lenses is on the horizon and has high potential to impact a large number of patients providing efficacious treatment compared to current topical treatments.

Dry eye: why artificial tears are not always the answer

Dry eye disease (DED) is a multifactorial disease that manifests in patients with a variety of symptoms and signs such as ocular pain, visual issues, rapid tear evaporation and/or decreased tear production. It is a global health problem and is the leading cause of optometry and ophthalmology clinic visits. The mainstay therapy for DED is artificial tears (ATs), which mimics tears and improves tear stability and properties. ATs have been found to improve symptoms and signs of disease in all DED subtypes, including aqueous deficient DED and evaporative DED. However, given the heterogeneity of DED, it is not surprising that ATs are not effective in all patients. When AT fails to relieve symptoms and/or signs of DED, it is critical to identify the underlying contributors to disease and escalate therapy appropriately. This includes underlying systemic diseases, meibomian gland dysfunction, anatomical abnormalities and neuropathic dysfunction. Thus, this review will discuss the benefits and limitations of ATs and review conditions when escalation of therapy should be considered in DED.

Oculoplastic aspects of ocular surface disease and their management

The normal structure and function of the eyelids, eyelashes, conjunctival fornices, and lacrimal system are essential for the health of the ocular surface, and abnormalities of these structures accompany many cases of ocular surface disease. We describe the role of oculoplastic intervention in the context of ocular surface disease, focusing on blink disorders, lagophthalmos, entropion, lid scarring and keratinization, trichiasis, and punctal and lacrimal sac disease.

Cross-linked hyaluronic acid gel occlusive device for the treatment of dry eye syndrome

Purpose

A new cross-linked hyaluronic acid (xlHA) gel occlusive device was assessed for safety and efficacy in the treatment of dry eyes.

Methods

This was an institutional review board-approved, single-site, open-label, prospective study to assess the efficacy and safety of placing the xlHA gel in the lower canaliculus. Seventy-four participants aged 25-95 years with dry eyes, who failed treatment with artificial tears, were included. Patients were assessed with corneal slit lamp examination with fluorescein staining and with Schirmer's test, breakup time (TBUT), and tear meniscus height (TMH) at baseline, 1 month, and 3 months. Patients were followed at 6 months with a telephone questionnaire. The procedure entailed inserting ~0.2 mL of xlHA gel into each lower lid canaliculus with a syringe and lacrimal irrigator. Patients were followed for adverse events.

Results

Sixty-three patients completed the study (48 females, 15 males), with an average age of 67 years. Slit lamp demonstrated improved corneal fluorescein staining. Schirmer's tests demonstrated an average increase over baseline of 3.67 mm after 3 months. TBUT improved 87% and TMH increased by 57% at 3 months over baseline. All objective measures were statically significant. There was one case of conjunctivitis that resolved and was felt to be an incidental viral infection.

Conclusion

The xlHA Occlusive Device offers a new, safe, and effective method to treat dry eyes. It appears to have efficacy for at least 3 months on clinical examination. The xlHA gel demonstrated a good tolerance and safety profile.

A new surgical approach for punctal occlusion using fibrous tissue from under the lacrimal caruncle

Purpose

Surgical punctal occlusion is indispensable for the treatment of severe dry eye in cases where punctal-plug insertion is not applicable due to an enlarged or deformed punctum. However, permanent punctal occlusion is difficult in some cases. In our aim to establish a more reliable punctal occlusion, we have devised a new surgical approach for punctal occlusion.

Patients and methods

This study involved 20 puncta of 12 eyes of 12 patients (1 male and 11 females; mean age: 65.2 years) with severe aqueous-tear-deficient dry eye. A new surgical procedure for punctal occlusion using fibrous tissue from under the lacrimal caruncle into the diathermy-induced deepithelialized canaliculus as supporting tissue for punctal closure was performed. In all patients, the assessment of eye symptoms, as well as the condition of punctal occlusion by slit-lamp biomicroscopy, tear volume (tear-meniscus radius [TMR] measurement by meniscometry), the condition of precorneal tear film (graded by interferometry [IG]), measurement of fluorescein breakup time (FBUT), and scoring of ocular surface staining (fluorescein score of area [FSA] and density [FSD], and lissamine green score [LGS]) were performed, and the preoperative and 6-month-postoperative values were compared.

Results

In regard to the postoperative improvement of symptoms, 11 patients showed remarkable improvement, 1 patient showed improvement, and no reopening of the closed punctum was found in any patient. Test values were all significantly improved post surgery (all: P<0.05) as compared to those prior to surgery (respective values [mean ± SD], and the pre- and postoperative P-values were: TMR (mm) [0.18±0.08; 0.56±0.28, P=0.002], IG [4.3±0.9; 2.7±0.8, P=0.009], FBUT [0.4±0.6; 4.1±2.9, P=0.004], FSA [1.6±0.7; 0.7±0.9, P=0.03], FSD [2.7±0.7; 0.6±0.7, P=0.003], and LGS [5.1±2.7; 1.1±2.1, P=0.005]). Moreover, no postoperative complications were observed.

Conclusion

The findings of this study showed that our novel surgical procedure for punctal occlusion is highly successful and that it results in improved and more complete punctal occlusion.

Spontaneous Canalicular Plug Erosion After Punctal Plug Placement

PURPOSE

To describe a case of keratoconjunctivitis sicca treated with punctal plug placement with the first reported complication of subsequent plug erosion through the canaliculus and extrusion through the lid.

METHODS

Punctal plugs were placed in a patient with Sjogren syndrome for treatment of keratoconjunctivitis sicca. More than 12 years later, the plug was noted to have eroded through the canaliculus and extruded through the conjunctiva and lid.

RESULTS

The extruded plug was removed, and punctal cautery was performed on 2 other puncta with improved symptom control.

CONCLUSIONS

Plug extrusion through the conjunctiva and lid is a possible consequence of punctal plug placement.

Comprehensive Review of the Literature on Existing Punctal Plugs for the Management of Dry Eye Disease

Numerous designs of punctal and canalicular plugs are available on the market. This variety presents challenges to ophthalmologists when choosing punctal plugs for the management of various ocular conditions. The aim of this literature review is to provide a classification system for lacrimal occlusive devices based on their location and duration of action as well as to identify different characteristics of each one of them. We want to give a comprehensive overview on punctal and canalicular plugs including their manufacturing companies, indications, and complications that have been reported in various articles. PubMed and Google Scholar were used to identify articles written in English as well as few articles written in Japanese, Chinese, Slovak, and Spanish that had abstracts in English. Nine different companies that manufacture punctal and canalicular plugs were identified and their plugs were included in this review. Punctal and canalicular plugs are used in the management of various ocular conditions including dry eye disease and punctal stenosis as well as in ocular drug delivery. Although they are a relatively safe option, associated complications have been reported in the literature such as infection, allergic reaction, extrusion, and migration.

A Pragmatic Approach to the Management of Dry Eye Disease: Evidence into Practice

Dry eye disease (DED) is a highly prevalent chronic ocular disorder that can lead to significant discomfort and visual disturbance. It is a potentially debilitating condition that can have significant negative impact on quality of life. A diverse range of management options exists for DED, including tear supplement products, anti-inflammatory agents, immunomodulators, punctal occlusive devices, and environmental modifiers. Although the availability of a variety of treatment approaches provides clinical flexibility and can enable individualized care, it can also complicate clinical management decisions and lead to variability in the nature of the clinical care provided to patients. By considering two dry eye case scenarios, this review evaluates the currently available evidence relating to DED therapy to describe a pragmatic clinical approach to best-practice management of dry eye patients.

Punctal Plug Retention Rates for the Treatment of Moderate to Severe Dry Eye: A Randomized, Double-Masked, Controlled Clinical Trial

PURPOSE

To compare retention rates of Super Flex (Eagle Vision, Memphis, Tennessee, USA; Softplug-Oasis Medical Inc, Glendora, California, USA) vs Parasol (Odyssey Medical, Memphis, Tennessee, USA; Beaver Visitec International, Waltham, Massachusetts, USA) punctal plugs.

DESIGN

Randomized, double-masked, interventional controlled clinical trial.

METHODS

Institutional study at Hotel Dieu Hospital (Queen's University) of 50 eyes, from patients with moderate to severe dry eye. Each eye from eligible patients was separately randomized to receive Super Flex or Parasol punctal plugs. The main outcome measure was plug retention at 6 months. Secondary outcome measures included objective tests of Schirmer I (mm), tear meniscus height (mm), tear break-up time (s), inferior fluorescein corneal staining (National Eye Institute [NEI] scale), and average lissamine green conjunctival staining (NEI scale).

RESULTS

Punctal plug retention was significantly different at 6 months (P = .011). Sixty-eight percent of Parasol plugs were retained compared to 32% of Super Flex plugs. Parasol plugs required less frequent artificial tear use at 6 months (P = .024). There was a statistically significant improvement in all secondary outcome measures (Schirmer, tear meniscus height, tear break-up time, fluorescein corneal staining) at 6 months within plug groups except conjunctival staining. There were no additional significant differences between groups and no plug complications reported.

CONCLUSIONS

Punctal plugs improve symptoms of moderate to severe dry eye; however, retention rates differ significantly. These data will allow us to guide patient decision making for the safe and effective treatment of punctal plugs for moderate to severe dry eye.

Safety and Efficacy of Lacrimal Drainage System Plugs for Dry Eye Syndrome: A Report by the American Academy of Ophthalmology

OBJECTIVE

To review the published literature assessing the efficacy and safety of lacrimal drainage system plug insertion for dry eye in adults.

METHODS

Literature searches of the PubMed and Cochrane Library databases were last conducted on March 9, 2015, without date restrictions and were limited to English language abstracts. The searches retrieved 309 unique citations. The primary authors reviewed the titles and abstracts. Inclusion criteria specified reports that provided original data on plugs for the treatment of dry eyes in at least 25 patients. Fifty-three studies of potential relevance were assigned to full-text review. The 27 studies that met the inclusion criteria underwent data abstraction by the panels. Abstracted data included study characteristics, patient characteristics, plug type, insertion technique, treatment response, and safety information. All studies were observational and rated by a methodologist as level II or III evidence.

RESULTS

The plugs included punctal, intracanalicular, and dissolving types. Fifteen studies reported metrics of improvement in dry eye symptoms, ocular-surface status, artificial tear use, contact lens comfort, and tear break-up time. Twenty-five studies included safety data. Plug placement resulted in ≥50% improvement of symptoms, improvement in ocular-surface health, reduction in artificial tear use, and improved contact lens comfort in patients with dry eye. Serious complications from plugs were infrequent. Plug loss was the most commonly reported problem with punctal plugs, occurring on average in 40% of patients. Overall, among all plug types, approximately 9% of patients experienced epiphora and 10% required removal because of irritation from the plugs. Canaliculitis was the most commonly reported problem for intracanalicular plugs and occurred in approximately 8% of patients. Other complications were reported in less than 4% of patients on average and included tearing, discomfort, pyogenic granuloma, and dacryocystitis.

CONCLUSIONS

On the basis of level II and III evidence in these studies, plugs improve the signs and symptoms of moderate dry eye that are not improved with topical lubrication, and they are well tolerated. There are no level I studies that describe the efficacy or safety of lacrimal drainage system plugs.

Dry eye disease: A review of diagnostic approaches and treatments

Dry eye (DE) is a common ocular disease that results in eye discomfort, visual disturbance and substantially affects the quality of life. It has a multifactorial etiology involving tear film instability, increased osmolarity of the tear film and inflammation of the ocular surface with potential damage to the ocular surface. This review discusses the classification, diagnostic approaches and treatments of DE.

Post-LASIK dry eye

Laser-assisted in situ keratomileusis (LASIK) is a frequently performed corneal refractive surgery with excellent refractive outcomes. The most common complication of LASIK is dry eyes, with virtually all patients developing some degree of dryness in the immediate postoperative period. Identifying preoperative dry eyes, and conscientious attention and treatment in the perioperative time period, can lead to enhanced patient satisfaction and more accurate visual outcomes. Improved understanding of the development of dry eyes after LASIK will advance our understanding of the complex pathophysiology of dry eye disease.

Diagnostic procedures and management of dry eye

Dry eye disease or dysfunctional tear syndrome is among the most frequent diagnoses in ophthalmology. It is a multifactorial disease of the ocular surface and tear film which results in ocular discomfort, visual disturbances, and tear instability with potential damage to the cornea and conjunctiva. Risk factors for dry eye syndrome include age, sex (female gender), race, contact lens wear, environment with low humidity, systemic medications, and autoimmune disorders. The aim of this paper is to present the systematic classification, epidemiology, diagnostic procedures, and advances in the management of dry eye disease. The recent improvements in comprehending the underlying etiologic factors will inevitably improve future classifications and diagnostic abilities leading to more effective therapeutic options. Treatment of this highly prevalent condition can drastically improve the quality of life of individuals and prevent damage to the ocular surface.

A review of the complications of lacrimal occlusion with punctal and canalicular plugs

Punctal and canalicular plugs are widely used for both temporary and permanent occlusion of the lacrimal puncta in dry eyes. There are many designs and materials available on the market. While their efficacy in improving dry eye symptoms is widely proven, the gamut of complications associated with these devices have never been subject to a general review, although there are numerous case series in the literature associated with one particular device. This review aims to examine the track record of a variety of plugs currently in use, to review the management of complications, and propose strategies for both the prevention of these complications and their treatment.

An investigation of the efficacy of a novel ocular lubricant

OBJECTIVE

To investigate the efficacy of a novel ocular lubricant compared with a commercially marketed ocular lubricant in a group of noncontact lens wearers currently using over-the-counter products for the management of symptoms of moderate to severe dry eye.

METHODS

This was a prospective, double-masked study that randomized 110 subjects in a ratio of 1:1 to receive a novel ocular lubricant (test group) or a marketed ocular lubricant (control group). Subjects were instructed to instill the lubricant eye drops at least three times daily. After enrollment, subjects were evaluated at baseline and at 7 and 30 days. They were also required to complete a series of home-based subjective questionnaires after 15 days. Main outcomes were subjective symptoms and objective clinical assessment at 7 and 30 days.

RESULTS

The test group had higher overall comfort ratings than the control group (P = 0.012). Seventy-one percent of the test group and 57% of the control group said the drops used "somewhat" or "definitely" improved ocular comfort; 62% of the test group had greater end-of-day comfort compared with 45% of the control group (P = 0.015). There were no between-group differences in visual acuity, tear quality or quantity, corneal staining, conjunctival staining, or bulbar and limbal conjunctival hyperemia.

CONCLUSIONS

The novel ocular lubricant offers equivalent or superior comfort compared with a marketed lubricant eye drop. Objective clinical outcomes were not statistically significantly different between the two groups.

Dry eye disease

Dry eye (DED) is a multifactorial disease that results in symptoms of discomfort, visual disturbance, and tear film instability with potential damage to the ocular surface, accompanied by increased osmolarity of the tear film and inflammation. DED is a common clinical problem and is among the most frequent diagnoses in ophthalmology. It substantially affects quality of life because of the constant ocular discomfort and decrease in visual function. This review discusses the etiology, classification, diagnosis procedures, clinical, and surgical treatments of dry eye.

Management of dysfunctional tear syndrome: a Canadian consensus

Dry eye complaints are common, have a diverse etiology, and result from disruption of the normal tear film; hence, the term "dysfunctional tear syndrome." Recent research has shown that ocular surface disorders have an inflammatory origin, that inflammation of the ocular surface does not always manifest as "red eye," and that a patient does not have to have a systemic autoimmune disease to experience a local, ocular autoimmune event. A panel of Canadian cornea and external disease subspecialists met and developed a questionnaire and treatment algorithm to aid the comprehensive ophthalmologist. Management of ocular surface disorders begins with a review of the patient's medical history, with particular attention to medication use, and a thorough ophthalmological examination. Use of a simple questionnaire can aid in the diagnosis. A variety of treatment modalities are available, the most effective of which are those that target the underlying inflammatory process with the goal of restoring the normal tear film. A treatment algorithm is presented that matches the severity of symptoms with the intensity of treatment. Lifestyle modifications, regular hygiene, and tear supplements may be sufficient in patients with mild symptoms. Anti-inflammatory medications (topical cyclosporin A, short courses of topical steroids, and [or] oral tetracyclines) and physical measures (punctal plugs, moisture-retaining eye wear) are implemented for those with moderate-to-severe symptoms. Autologous serum tears, scleral contact lenses, and surgery are reserved for patients with severe symptoms who have an unsatisfactory response to anti-inflammatory medications. Patients with lid disease or rosacea and those with allergic conditions should be identified during the initial encounter and should receive specific therapy to relieve their symptoms.

Effect of blinking on tear volume after instillation of midviscosity artificial tears

PURPOSE

To determine by optical coherence tomography (OCT) the effect of blinking on ocular surface tear volume after instillation of artificial tears.

DESIGN

Experimental study.

METHODS

Normal human eyes (n = 21) were imaged to obtain dimensions of the tear film and menisci during blinking. The imaging was carried out immediately and five minutes after the instillation of 35 microl midviscosity artificial tears (1.0% carboxymethylcellulose; Refresh Liquigel; Allergan, Irvine, California, USA). The exposed ocular surface area and the lid lengths were used to calculate the volumes.

RESULTS

Immediately after the instillation, total tear volume was increased (P < .001) compared with five minutes after the instillation, with the major increases in the lower tear meniscus volume and tear film volume. After the instillation, blinking caused tear loss in total tear volume because of the decrease of the lower tear meniscus volume (P < .05). In contrast, blinking increased the tear film volume (P < .05). At the end of the eye-opening period, tear film volume decreased and lower tear meniscus volume increased significantly (P < .05), with no significant changes in total tear volume (P > .05). During the blink cycle immediately after the instillation, net loss was evident in tear film volume, lower tear meniscus volume, and total tear volume (P < .05).

CONCLUSIONS

Blinking plays a crucial role in distribution and removal of instilled tears. When the tear system is overloaded, the increase in blink output helps restore balance.

New insights into the diagnosis and treatment of neurotrophic keratopathy

Abnormalities of the ocular surface can be acquired or inherited disorders of the central nervous system. Loss of neural stimulation from the sensory division of the trigeminal nerve or from the autonomic nervous system can have devastating consequences on corneal epithelial wound healing and the precorneal tear film, leading to decreased vision. The pathogenesis of neurotrophic keratopathy is reviewed, and treatment modalities are recommended.

Management and Therapy of Dry Eye Disease: Report of the Management and Therapy Subcommittee of the International Dry Eye WorkShop (2007)

The members of the Management and Therapy Subcommittee assessed current dry eye therapies. Each member wrote a succinct evidence-based review on an assigned aspect of the topic, and the final report was written after review by and with consensus of all subcommittee members and the entire Dry Eye WorkShop membership. In addition to its own review of the literature, the Subcommittee reviewed the Dry Eye Preferred Practice Patterns of the American Academy of Ophthalmology and the International Task Force (ITF) Delphi Panel on Dry Eye. The Subcommittee favored the approach taken by the ITF, whose recommended treatments were based on level of disease severity. the recommendations of the Subcommittee are based on a modification of the ITF severity grading scheme, and suggested treatments were chosen from a menu of therapies for which evidence of therapeutic effect had been presented.

Science and Strategy for Preventing and Managing Corneal Ulceration

ABSTRACT Corneal ulcers can cause significant loss of vision from scarring and astigmatism, but rapid management can limit the destruction and improve outcomes. Infectious ulcers usually resolve with antimicrobial treatment. Noninfectious ulcers, however, present a diagnostic and therapeutic challenge. They can often be resolved by eliminating toxic medications and providing surface support with lubrication and collagenase inhibitors, but resistant ulcers may need more aggressive therapy with bandage contact lenses, tarsorrhaphy, or autologous serum. Ulcers impending perforation require urgent surgical management (e.g., tissue glue, conjunctival flaps, or keratoplasty). Topical steroids are useful when the ulceration is secondary to inflammatory mediators, but they are contraindicated in corneal melts with minimal inflammation, such as those associated with Sjogren syndrome. Systemic immunomodulation is required in addition to topical therapy in the presence of autoimmune disease. Understanding of the pathological processes that occur in different types of corneal ulcers is essential to formulation of a logical and effective treatment plan. Newer, more targeted treatment modalities may offer treatment options that have greater efficacy and fewer adverse effects.

Nocturnal Lagophthalmos: An Overview and Classification

Nocturnal lagophthalmos is the inability to close the eyelids during sleep. Lagophthalmos is associated with exposure keratopathy, poor sleep, and persistent exposure-related symptoms. There are a variety of causes of lagophthalmos, grouped as proptosis/eye exposure etiologies and palpebral insufficiency etiologies. Although obvious lagophthalmos is usually detected, it is sometimes difficult to recognize obscure lagophthalmos, due either to eyelash obstruction or overhang of the upper lid anterior and inferior to the most superior portion of the lower lid in a closed position. We present a novel classification system and illustrations of obvious and obscure lagophthalmos. A diagnosis can usually be made with a focused history and slit lamp examination. Treatment is multipronged and may include minor procedures or ocular surgery to correct the lid malposition; natural, topical or oral agents; and punctal plugs to manage ocular surface effects. Correct and timely diagnosis allows greater opportunity for relief of patient suffering and prevention of severe ocular surface pathology, as well as educated planning for future ocular surgical procedures.